US7015368B2 - Purification process of thermoprocessable tetrafluoroethylene copolymers - Google Patents
Purification process of thermoprocessable tetrafluoroethylene copolymers Download PDFInfo
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- US7015368B2 US7015368B2 US10/205,494 US20549402A US7015368B2 US 7015368 B2 US7015368 B2 US 7015368B2 US 20549402 A US20549402 A US 20549402A US 7015368 B2 US7015368 B2 US 7015368B2
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- 229920001577 copolymer Polymers 0.000 title claims abstract description 23
- 238000000746 purification Methods 0.000 title claims abstract description 10
- 238000005406 washing Methods 0.000 claims abstract description 89
- 229920000642 polymer Polymers 0.000 claims abstract description 59
- 239000004816 latex Substances 0.000 claims abstract description 56
- 229920000126 latex Polymers 0.000 claims abstract description 56
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 claims abstract description 27
- 239000002253 acid Substances 0.000 claims abstract description 16
- 239000003792 electrolyte Substances 0.000 claims abstract description 16
- 238000010907 mechanical stirring Methods 0.000 claims abstract description 16
- 239000007864 aqueous solution Substances 0.000 claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 41
- 238000000034 method Methods 0.000 claims description 35
- 239000000843 powder Substances 0.000 claims description 30
- 238000003756 stirring Methods 0.000 claims description 27
- 238000006116 polymerization reaction Methods 0.000 claims description 18
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 17
- 229910017604 nitric acid Inorganic materials 0.000 claims description 17
- 244000144992 flock Species 0.000 claims description 11
- 238000001035 drying Methods 0.000 claims description 10
- 229910052739 hydrogen Inorganic materials 0.000 claims description 7
- 239000006185 dispersion Substances 0.000 claims description 6
- 239000000839 emulsion Substances 0.000 claims description 5
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 claims description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- 125000003709 fluoroalkyl group Chemical group 0.000 claims description 4
- XUCNUKMRBVNAPB-UHFFFAOYSA-N fluoroethene Chemical compound FC=C XUCNUKMRBVNAPB-UHFFFAOYSA-N 0.000 claims description 4
- 239000000178 monomer Substances 0.000 claims description 4
- 239000006228 supernatant Substances 0.000 claims description 4
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 3
- 239000005977 Ethylene Substances 0.000 claims description 3
- 150000001336 alkenes Chemical class 0.000 claims description 3
- 238000010923 batch production Methods 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- 238000010790 dilution Methods 0.000 claims description 3
- 239000012895 dilution Substances 0.000 claims description 3
- 125000004400 (C1-C12) alkyl group Chemical group 0.000 claims description 2
- MIZLGWKEZAPEFJ-UHFFFAOYSA-N 1,1,2-trifluoroethene Chemical group FC=C(F)F MIZLGWKEZAPEFJ-UHFFFAOYSA-N 0.000 claims description 2
- QMIWYOZFFSLIAK-UHFFFAOYSA-N 3,3,3-trifluoro-2-(trifluoromethyl)prop-1-ene Chemical compound FC(F)(F)C(=C)C(F)(F)F QMIWYOZFFSLIAK-UHFFFAOYSA-N 0.000 claims description 2
- 125000004429 atom Chemical group 0.000 claims description 2
- 125000004122 cyclic group Chemical group 0.000 claims description 2
- 238000010908 decantation Methods 0.000 claims description 2
- 150000001993 dienes Chemical class 0.000 claims description 2
- 125000001033 ether group Chemical group 0.000 claims description 2
- 125000001153 fluoro group Chemical group F* 0.000 claims description 2
- 150000007522 mineralic acids Chemical class 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- 125000005429 oxyalkyl group Chemical group 0.000 claims description 2
- 125000004430 oxygen atom Chemical group O* 0.000 claims description 2
- 125000005010 perfluoroalkyl group Chemical group 0.000 claims description 2
- 125000000876 trifluoromethoxy group Chemical group FC(F)(F)O* 0.000 claims description 2
- 239000000499 gel Substances 0.000 description 49
- 150000001768 cations Chemical class 0.000 description 27
- 239000004094 surface-active agent Substances 0.000 description 12
- 239000000243 solution Substances 0.000 description 11
- 239000008187 granular material Substances 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 230000003287 optical effect Effects 0.000 description 10
- 239000003643 water by type Substances 0.000 description 9
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 8
- 238000005188 flotation Methods 0.000 description 8
- 239000000126 substance Substances 0.000 description 7
- 238000005345 coagulation Methods 0.000 description 6
- 230000015271 coagulation Effects 0.000 description 6
- 229920001897 terpolymer Polymers 0.000 description 6
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229910052700 potassium Inorganic materials 0.000 description 5
- 239000011591 potassium Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 230000003179 granulation Effects 0.000 description 4
- 238000005469 granulation Methods 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000004159 Potassium persulphate Substances 0.000 description 3
- -1 can be mentioned Chemical compound 0.000 description 3
- 238000010924 continuous production Methods 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 3
- 235000019394 potassium persulphate Nutrition 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000004457 water analysis Methods 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical compound CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- 238000011088 calibration curve Methods 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 2
- UUAGAQFQZIEFAH-UHFFFAOYSA-N chlorotrifluoroethylene Chemical group FC(F)=C(F)Cl UUAGAQFQZIEFAH-UHFFFAOYSA-N 0.000 description 2
- 238000004587 chromatography analysis Methods 0.000 description 2
- HCDGVLDPFQMKDK-UHFFFAOYSA-N hexafluoropropylene Chemical compound FC(F)=C(F)C(F)(F)F HCDGVLDPFQMKDK-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000011164 primary particle Substances 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000007669 thermal treatment Methods 0.000 description 2
- HNSDLXPSAYFUHK-UHFFFAOYSA-N 1,4-bis(2-ethylhexyl) sulfosuccinate Chemical compound CCCCC(CC)COC(=O)CC(S(O)(=O)=O)C(=O)OCC(CC)CCCC HNSDLXPSAYFUHK-UHFFFAOYSA-N 0.000 description 1
- HFNSTEOEZJBXIF-UHFFFAOYSA-N 2,2,4,5-tetrafluoro-1,3-dioxole Chemical class FC1=C(F)OC(F)(F)O1 HFNSTEOEZJBXIF-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 239000004262 Ethyl gallate Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- AFVFQIVMOAPDHO-UHFFFAOYSA-N Methanesulfonic acid Chemical compound CS(O)(=O)=O AFVFQIVMOAPDHO-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- YOALFLHFSFEMLP-UHFFFAOYSA-N azane;2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluorooctanoic acid Chemical class [NH4+].[O-]C(=O)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)C(F)(F)F YOALFLHFSFEMLP-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000368 destabilizing effect Effects 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 230000032050 esterification Effects 0.000 description 1
- 238000005886 esterification reaction Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000004702 methyl esters Chemical class 0.000 description 1
- 239000004530 micro-emulsion Substances 0.000 description 1
- 238000012667 polymer degradation Methods 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
- C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
- C08J3/075—Macromolecular gels
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F6/00—Post-polymerisation treatments
- C08F6/14—Treatment of polymer emulsions
- C08F6/16—Purification
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F6/00—Post-polymerisation treatments
- C08F6/14—Treatment of polymer emulsions
- C08F6/22—Coagulation
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
- C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
- C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08J2327/18—Homopolymers or copolymers of tetrafluoroethylene
Definitions
- the present invention relates to a purification process of thermoprocessable tetrafluoroethylene (TFE) copolymers to obtain polymers having high optical properties and suitable for applications in semicon, since they show very low levels of extractable cations.
- TFE thermoprocessable tetrafluoroethylene
- the invention relates to a process for obtaining thermoprocessable tetrafluoroethylene (TFE) copolymers substantially free from inorganic salts through latex washing under gel form, to obtain a final copolymer having a high purity degree, a low amount of extractable substances (as defined below) and high optical properties. Furthermore by the invention process also the residual surfactants are substantially reduced, by a thermal treatment.
- TFE thermoprocessable tetrafluoroethylene
- thermoprocessable copolymers are usable for the applications where high optical properties of the finished manufactured article are required, since low yellow index values and high whiteness values are obtained and therefore there are no coloration problems of the manufactured article.
- the powders of the present invention can be used also in the semicon industry where polymers having a low release of extractable substances are required.
- the coagulation process comprises the following steps:
- the powders obtained according to said conventional process have the drawback not to be suitable for the application in semicon since they show a high release of extractable substances. Besides they cannot be used for optical applications since they have a high yellow index value and a low whiteness index.
- the obtained polymer should be subjected to thermal treatments at high temperatures. This has the drawback to lead to partial polymer degradation.
- thermoprocessable tetrafluoroethylene (TFE) copolymers whereby it was possible to obtain copolymers suitable for the applications wherein manufactured articles having high optical properties are required or for the applications wherein it is required that the polymer has a low release of extractable substances, such for example in the semicon industry as above.
- thermoprocessable tetrafluoroethylene (TFE) copolymers comprising the following steps:
- thermoprocessable TFE copolymers which after the washing step B) contain extractable cations, excluding H + , in an amount lower than 1 ppm.
- the process of the present invention can be carried out in batch or in a continuous way.
- step A) for obtaining the polymer latex under the gel form is preferably carried out in a vessel equipped with baffles and stirring devices.
- the stirring devices are preferably pitched blade devices.
- Step A) of gel formation comprises the following steps:
- polymer under gel form it is meant that the polymer particles are immersed in the liquid phase and are joined each other by crossed bonds so to form a thick network.
- the gel properties significantly depend on the interactions between the polymer particles and the liquid phase. Indeed the retained liquid prevents the polymer network from being transformed into a compact mass, and the polymer network prevents the liquid from coming out from the gel.
- the gel consistence can range from a viscous fluid to a rather stiff solid.
- Steps 1)-3) are repeated until a residual amount of extractable cations (H+ excluded) lower than 1 ppm.
- the washing step B) is generally repeated for 3-10 times, preferably for 4-8 times.
- the polymer latex obtained from the polymerization in dispersion is fed in counter-current to a continuous flow washing column.
- the column has the following features:
- the polymer gel formation takes place in the upper part of the washing column.
- the polymer latex is directly fed to the first stage in the upper part of the column, where the polymer gel flocks are formed almost instantaneously.
- the washing of the gel flocks takes place during their gravitational segregation along the column, then the gel flocks flows out from the washing column bottom.
- the washing water flows in from the column bottom and flows out from the upper part, generally the first stage of the column.
- the acid electrolyte used to have the desired pH in step A) is fed into the multistage column.
- the feeding point of the acid electrolyte can vary along the column, so to regulate the gel pH at the column outlet.
- the fed amount of acid electrolyte is such to determine at the first stage of the column pH conditions lower than or equal to 2, preferably between 0.4 and 1.6, to favour the polymer gel formation.
- the stirrer peripheral rate is lower than 0.6 m/s, preferably between 0.1 and 0.5 m/s.
- the temperature inside the washing column is generally in the range 10° C. -40° C.
- the linear rate of the washing water in the column must be lower than 1 cm/sec. By operating in said way there are negligible losses of polymer, lower than 0.1% by weight.
- the gel washing efficiency in the washing column of the present invention depends on the residence time of the gel flocks in the column.
- the residence time increases as the column length increases. Therefore the higher the stage number, the higher the washing efficiency.
- the Applicant has furthermore found that the gel washing efficiency improves as the stirring rate increases. In fact an increase of the stirring rate allows to decrease the gel flock size and therefore it facilitates the washing efficiency.
- the ratio between the washing water flow rate and the latex flow rate, in litres/h, depends on the column stage number and is generally in the range 1:1-10:1, preferably 1.5:1-5:1.
- inorganic acids preferably nitric acid, hydrochloric acid
- nitric acid is preferred.
- thermoprocessable TFE copolymers the polymers obtained by polymerization of TFE with one or more monomers containing at least one unsaturation of ethylene type, are meant.
- hydrogenated olefins can be mentioned, preferably in addition to the above comonomers.
- examples of hydrogenated olefins are ethylene, propylene, butene and iso-butene.
- the comonomer amount in the copolymer is such that the copolymer is thermoprocessable. Generally it is in the range 1-18% by weight, preferably 2-10% by weight, and it depends on the type of comonomer.
- the invention polymers are thermoprocessable and have a melt viscosity in the range 10 3 -10 8 Pa.s.
- chain transfer agents are used to obtain molecular weights giving the indicated viscosities.
- the skilled in the art knows how to work to obtain said known thermoprocessable polymers of the prior art.
- the polymer latex from which gels are obtained as above described is obtained by polymerization in dispersion (emulsion) of TFE in the presence of comonomers as above said.
- the primary particles of the latex polymer have sizes from 0.1 to 0.4 micron.
- the process for obtaining the latex can also be carried out in microemulsion. See for example U.S. Pat. Nos. 4,864,006, 4,990,283 and EP 969,027. In this case the diameter of the latex primary particles ranges from 0.01 to 0.1 micron.
- thermoprocessable TFE copolymers which after the separation of the polymer powder from the mother liquors are substantially free from extractable cations (H+ excluded).
- thermoprocessable TFE copolymers which contain an amount of extractable cations lower than 1 ppm.
- a drying step can be carried out on the thermoprocessable polymer powder obtained according to the process of the invention, at the end of the process steps.
- the drying temperature is generally in the range 230°-280° C.
- the amount of extractable cations, excluding H + is lower than 1 ppm.
- the surfactant amount is lower than the analytical detectable limit, in practice it is substantially removed from the polymer powders.
- thermoprocessable TFE copolymers which contain an amount of extractable cations lower than 1 ppm and of substantially absent residual surfactants, lower than the analytical limits (10 ppm), lower than about 10 ppm.
- copolymer losses in the purification process carried out according to the present invention are negligible, of the order of 0.1% by weight.
- thermoprocessable polymers of the invention are particularly suitable to prepare manufactured articles to be used in the semicon industry, for example to prepare tanks and piping systems (pipes and fitting), since they do not release extractable substances. Another use is for optical applications having improved properties.
- Cations are determined by ionic chromatography, by injecting into the column the mother liquors or the washing waters.
- the potassium cation is the one present in higher amounts, for this reason only this cation is reported in the Tables.
- the method used to determine the various cations is herein exemplified for the potassium ion, the same method is repeated for the other cations.
- the potassium cation has been determined on mother liquors and washing waters, in balance with the gel, and the found amount has been related to the total amount of powder.
- the peak area is related to the amount of K + present in the tested waters by calibration curve (operating conditions: Dionex 4500i chromatograph equipped with conductimetric cell—Precolumn and separatory column CG12-CS12—Eluent methansul-phonic acid 20 mN—eluting flow at 1 ml/min—Autoregenerator CSRS—100 ⁇ l loop).
- the method detectable limit is 0.15 ppm.
- the surfactant amount in both dry and wet powder has been determined by gas-chromatographic analysis of the corresponding methyl ester, according to the following procedure:
- 0.5 g of powder are wetted with ethanol and brought to basic pH with a NH 4 OH solution.
- the powder is dried under nitrogen flow.
- To the dried powder 2 ml of acid methanol are added. Esterification is let happen at 70° C. for 16 hours in an hermetically sealed test tube. At this point to the mixture 0.5 ml of Delifrene® A113 and 4 ml of water are added.
- the peak area is converted into the present surfactant amount by calibration curve.
- the surfactant used for obtaining the latex of the Examples is the ammonium perfluorooctanoate salt (PFOA).
- the determination method detectable limit is 10 ppm.
- 16 litres of latex of a terpolymer TFE/PMVE/PPVE Hyflon MFA 640® at 18% w/w, obtained by polymerization in the presence of potassium persulphate, are introduced in a 50 litres reactor.
- the mixture is put under mechanical stirring (pitched blade stirrer ⁇ stirring specific power 3 KW/m 3 ) and added, under stirring, with HNO 3 at 20% so to bring the latex pH to the value of 1.
- the latex is stirred until a gel is obtained.
- the water/gel mixture is put for 5 minutes under a stirring having specific power 0.5 KW/m 3 , sufficient to shatter the gel into flocks but that is such to leave them in close contact with the water without floating.
- the washing procedure is repeated for further 5 times.
- the mixture is stirred until obtaining the powder flotation by applying to the stirrer a specific power of 5 KW/m 3 . Stirring is stopped and the underlying water is separated from the wet fine powder.
- the pH data of the washing waters and the potassium cation amount calculated by the water analysis, converted into the amount present in the powder after each washing, are shown in Table 2.
- the potassium amount is lower than 1 ppm, also the amount of all the other cations present has been determined.
- the total amount of the cations present results lower than 1 ppm.
- the powder after drying at 270° C. for 6 hours is extruded.
- the specimens obtained after moulding of the granules deriving from the extrusion have Yellow Index and Whiteness values as shown in Table 3.
- the optical properties result very good having obtained a low Yellow Index value and a high Whiteness value.
- 16 liters of latex of a terpolymer TFE/PMVE/PPVE Hyflon MFA 640® at 18% w/w, obtained by polymerization in the presence of potassium persulphate, are introduced in a 50 liters reactor.
- the mixture is put under mechanical stirring (pitched blade stirrer—stirring specific power 3 KW/m 3 ) and added, under stirring, with HNO 3 at 20% so to bring the latex pH to the value of 1.
- the latex is stirred until a gel is obtained.
- the washing procedure is repeated for further 5 times.
- the mixture is stirred until obtaining the powder flotation by applying to the stirrer a specific power of 5 KW/m 3 . Stirring is stopped and the underlying water is separated from the wet fine powder.
- the pH data of the washing waters and the potassium cation amount calculated by the water analysis, converted into the amount present in the powder after each washing, are shown in Table 2.
- the potassium amount is lower than 1 ppm, also the amount of all the other cations present has been determined.
- the total amount of the cations present results lower than 1 ppm.
- the powder after drying at 260° C. for 6 hours is extruded.
- the specimens obtained after moulding of the granules deriving from the extrusion have Yellow Index and Whiteness values as shown in Table 3.
- the latex is stirred until obtaining the powder flotation by applying to the stirrer a specific power of 5 KW/m 3 . Stirring is stopped and all the water (12 litres) underlying the wet fine powder is removed.
- the wet powder is subjected to washing with 20 litres of water (pH 7) for a time of 5 minutes under stirring, by applying to the stirrer a specific power of 3 KW/m 3 .
- the pH in the single washings is shown in Table 2. Stirring is stopped and 20 litres of washing water are removed.
- the washing procedure is repeated for further 5 times.
- the pH data of the washing waters and the potassium cation amount calculated by the water analysis, converted into the amount present in the powder after each washing, are shown in Table 2.
- the potassium amount, as it can be seen in the Table, even after 5 washings is higher than 1 ppm and it does not undergo reductions for subsequent washings. In this case it is superfluous to determine the amount of all the other cations present.
- the powder after drying at 270° C. for 5 hours is extruded.
- the specimens obtained after moulding of the granules deriving from the extrusion by the methodology illustrated in the characterization Examples have Yellow Index and Whiteness values as shown in Table 3.
- the optical properties are poor.
- the latex of a terpolymer TFE/PMVE/PPVE Hyflon MFA 640® is fed in counter-current to a continuous flow washing column.
- the column is a multistage column and is equipped in each stage with baffles and with 4 blade disc turbines for the mechanical stirring.
- the column diameter is of 0.11 m, the height is of 1.5 m.
- the stage number is 11, the height of each stage is of 0.11 m.
- Conic discs having a height of 0.03 m separate the stages the one from the other. Two calm zones are planned respectively at the top and at the bottom of the column.
- the stirring peripheral rate is 0.4 m/s.
- the temperature inside the washing column is 30° C.
- the latex having a polymer concentration equal to 18% by weight is directly fed to the first stage of the column with a flow rate equal to 16 litres/h.
- the washing water comes in from the bottom of the column and flows out from the upper part of the column.
- the ratio between the water flow rate and the latex flow rate is equal to 2.
- a HNO 3 solution at 20% by weight is fed to the multistage column in correspondence of the 6th stage.
- the polymer after washing has a Whiteness value of 78 and a yellow index value equal to 1.55.
- the potassium concentration (determined as above) in the polymer granules after granulation, flotation and drying at 270° C. for 6 hours results of 0.15 ppm.
- the amount of all the other cations present has been determined.
- the total amount of the cations present, H + comprised, results lower than 1 ppm.
- the surfactant amount in the granules results lower than the analytical detectable limits.
- the latex of a terpolymer TFE/PMVE/PPVE Hyflon MFA 640® at 18% by weight concentration is fed to the first stage of the washing column of Example 4 with a flow rate of 16 l/h.
- the ratio between the water flow rate and the latex flow rate is equal to 1.5.
- a HNO 3 solution at 20% by weight is fed to the multistage column in correspondence of the 6th stage.
- the polymer after washing has a Whiteness value of 76 and a yellow index value of 1.7.
- the potassium cation concentration in the polymer granules after granulation, flotation and drying at 270° C. for 6 hours results of 0.18 ppm.
- the amount of all the other cations present has been determined.
- the total amount of the cations present, H + comprised, results lower than 1 ppm.
- the surfactant amount in the granules results lower than the analytical detectable limits.
- the latex of a terpolymer TFE/PMVE/PPVE Hyflon MFA 640® at 18% by weight concentration is fed to the first stage of the washing column of Example 4 with a flow rate of 10 l/h.
- the ratio between the water flow rate and the latex flow rate is equal to 5.5.
- a HNO 3 solution at 20% by weight is fed at the bottom of the multistage column in correspondence of the last stage.
- the polymer after washing has a Whiteness value of 79 and a yellow index value of 1.5.
- the potassium cation concentration in the polymer granules after granulation, flotation and drying at 275° C. for 4 hours results of 0.15 ppm.
- the amount of all the other cations present has been determined.
- the total amount of the cations present, H + comprised, results lower than 1 ppm.
- the surfactant amount in the granules results lower than the analytical detectable limits.
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US10/790,680 US7157550B2 (en) | 2001-07-26 | 2004-03-03 | Purification process of thermoprocessable tetrafluoroethylene copolymers |
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IT2001MI001614A ITMI20011614A1 (it) | 2001-07-26 | 2001-07-26 | Processo di purificazione di copolimeri termoprocessabili del tetrafluoroetilene |
ITMI2001A001614 | 2001-07-26 |
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US10/790,680 Expired - Lifetime US7157550B2 (en) | 2001-07-26 | 2004-03-03 | Purification process of thermoprocessable tetrafluoroethylene copolymers |
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US (2) | US7015368B2 (de) |
EP (1) | EP1279681B1 (de) |
JP (1) | JP4264230B2 (de) |
DE (1) | DE60233776D1 (de) |
IT (1) | ITMI20011614A1 (de) |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060047084A1 (en) * | 2004-08-25 | 2006-03-02 | Asahi Glass Company, Limited | Fluorocopolymer |
US20060122299A1 (en) * | 2004-12-02 | 2006-06-08 | Lia Kouchachvili | High performance P(VDF-TrFE) copolymer for pyroelectric conversion |
Families Citing this family (11)
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WO2005007709A1 (ja) * | 2003-07-03 | 2005-01-27 | Daikin Industries, Ltd. | フルオロポリマー凝集体及びその製造方法 |
ITMI20041253A1 (it) * | 2004-06-22 | 2004-09-22 | Solvay Solexis Spa | Gel di fluoroelastomeri |
ITMI20041251A1 (it) | 2004-06-22 | 2004-09-22 | Solvay Solexis Spa | Gel di perfluoroelastomeri |
ITMI20041572A1 (it) * | 2004-07-30 | 2004-10-30 | Solvay Solexis Spa | Capolimeri termoprocessabili a base di tfe |
ITMI20051397A1 (it) * | 2005-07-21 | 2007-01-22 | Solvay Solexis Spa | Polveri fini di fluoropolimeri |
JP5343355B2 (ja) * | 2005-10-26 | 2013-11-13 | 旭硝子株式会社 | 含フッ素乳化剤の残留量が少ないフッ素樹脂およびその製造方法 |
CN102443091B (zh) * | 2011-10-25 | 2013-07-24 | 中昊晨光化工研究院 | 一种聚全氟乙丙烯树脂的凝聚洗涤方法 |
EP2928946B1 (de) * | 2012-12-05 | 2019-02-27 | Solvay Specialty Polymers Italy S.p.A. | In der schmelze verarbeitbare perfluorpolymere mit verbesserten thermischen und mechanischen eigenschaften nach temperieren |
CN114644723A (zh) * | 2014-06-05 | 2022-06-21 | 索尔维特殊聚合物意大利有限公司 | 热处理后具有改进的热和机械特性的可熔融加工的全氟聚合物 |
EP3957656A4 (de) * | 2019-04-16 | 2022-12-28 | Daikin Industries, Ltd. | Verfahren zur herstellung von fluorpolymerpulver |
CN114437255A (zh) * | 2020-11-04 | 2022-05-06 | 浙江蓝天环保高科技股份有限公司 | 一种含氟聚合物的提纯方法 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4864006A (en) | 1986-06-26 | 1989-09-05 | Ausimont S.P.A. | Process for the polymerization in aqueous dispersion of fluorinated monomers |
US4990283A (en) | 1986-06-26 | 1991-02-05 | Ausimont S.P.A. | Microemulsions containing perfluoropolyethers |
EP0969027A1 (de) | 1998-07-02 | 2000-01-05 | Ausimont S.p.A. | TFE-Polymerisationsverfahren |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB129022A (en) | 1916-09-25 | 1919-07-10 | Marie Joseph Cornu | Improvements in or relating to Mercury Vapour Lamps. |
FR1384989A (fr) * | 1963-01-25 | 1965-01-08 | Montedison Spa | Copolymères fluorés et procédé pour leur préparation |
NL143244B (nl) * | 1964-07-31 | 1974-09-16 | Montedison Spa | Werkwijze om fluor bevattende terpolymeren te bereiden. |
US3579474A (en) * | 1968-12-16 | 1971-05-18 | Du Pont | Elastomeric copolymers of tetrafluoroethylene containing phenoxyethyl groups,and their vulcanization |
US3956000A (en) * | 1972-07-21 | 1976-05-11 | Hoechst Aktiengesellschaft | Fluorocarbon waxes and process for producing them |
US4675380A (en) * | 1985-10-25 | 1987-06-23 | E. I. Du Pont De Nemours And Company | Melt-processible tetrafluoroethylene/perfluoroolefin copolymer granules and processes for preparing them |
US5856417A (en) * | 1996-10-29 | 1999-01-05 | Asahi Glass Company Ltd. | Fluorine-containing copolymer |
CA2382525A1 (en) * | 2000-06-01 | 2001-12-06 | 3M Innovative Properties Company | High purity fluoropolymers |
ITMI20011615A1 (it) * | 2001-07-26 | 2003-01-26 | Ausimont Spa | Processo di ottenimento di p0lveri fini non termoprocessabili di ptfeomopolimero o ptfe modificato |
-
2001
- 2001-07-26 IT IT2001MI001614A patent/ITMI20011614A1/it unknown
-
2002
- 2002-07-23 EP EP02016467A patent/EP1279681B1/de not_active Expired - Lifetime
- 2002-07-23 DE DE60233776T patent/DE60233776D1/de not_active Expired - Lifetime
- 2002-07-25 JP JP2002216870A patent/JP4264230B2/ja not_active Expired - Lifetime
- 2002-07-25 RU RU2002120310/04A patent/RU2288922C2/ru not_active IP Right Cessation
- 2002-07-26 US US10/205,494 patent/US7015368B2/en not_active Expired - Lifetime
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2004
- 2004-03-03 US US10/790,680 patent/US7157550B2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4864006A (en) | 1986-06-26 | 1989-09-05 | Ausimont S.P.A. | Process for the polymerization in aqueous dispersion of fluorinated monomers |
US4990283A (en) | 1986-06-26 | 1991-02-05 | Ausimont S.P.A. | Microemulsions containing perfluoropolyethers |
EP0969027A1 (de) | 1998-07-02 | 2000-01-05 | Ausimont S.p.A. | TFE-Polymerisationsverfahren |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060047084A1 (en) * | 2004-08-25 | 2006-03-02 | Asahi Glass Company, Limited | Fluorocopolymer |
US7429631B2 (en) * | 2004-08-25 | 2008-09-30 | Asahi Glass Company, Limited | Fluorocopolymer |
US20060122299A1 (en) * | 2004-12-02 | 2006-06-08 | Lia Kouchachvili | High performance P(VDF-TrFE) copolymer for pyroelectric conversion |
US7323506B2 (en) * | 2004-12-02 | 2008-01-29 | Natural Resources Canada | High performance P(VDF-TrFE) copolymer for pyroelectric conversion |
Also Published As
Publication number | Publication date |
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US20040167272A1 (en) | 2004-08-26 |
EP1279681B1 (de) | 2009-09-23 |
ITMI20011614A0 (it) | 2001-07-26 |
EP1279681A2 (de) | 2003-01-29 |
US7157550B2 (en) | 2007-01-02 |
EP1279681A3 (de) | 2004-01-21 |
JP4264230B2 (ja) | 2009-05-13 |
DE60233776D1 (de) | 2009-11-05 |
RU2288922C2 (ru) | 2006-12-10 |
ITMI20011614A1 (it) | 2003-01-26 |
RU2002120310A (ru) | 2004-02-27 |
JP2003082019A (ja) | 2003-03-19 |
US20030092860A1 (en) | 2003-05-15 |
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